erratic
C1Formal to Neutral. Common in written analysis, reports, journalism, and educated speech.
Definition
Meaning
irregular, unpredictable, or inconsistent in movement, behaviour, or quality.
Deviating from the usual or expected course; lacking consistency, regularity, or uniformity. Often describes behaviour, performance, patterns, or movement that cannot be relied upon.
Linguistics
Semantic Notes
Carries a negative connotation of unreliability and capriciousness. It describes a *pattern* of inconsistency, not a single isolated event.
Dialectal Variation
British vs American Usage
Differences
No significant difference in core meaning or frequency. Slight preference in UK English for describing 'erratic driving' in legal/insurance contexts.
Connotations
Equally negative in both dialects. In US business contexts, can imply volatile stock performance or managerial style.
Frequency
Slightly more common in UK written news, particularly about weather ('erratic showers'), sports performance, and political behaviour.
Vocabulary
Collocations
Grammar
Valency Patterns
prove/be/become/seem erraticdescribe something as erraticerratic in (his behaviour)Vocabulary
Synonyms
Strong
Neutral
Weak
Vocabulary
Antonyms
Phrases
Idioms & Phrases
- “All over the shop/the map (UK/US informal equivalent for erratic behaviour/performance)”
Usage
Context Usage
Business
The company's erratic earnings reports have worried investors.
Academic
The erratic data points were excluded from the final analysis as outliers.
Everyday
The bus service has been so erratic lately that I've started cycling.
Technical
The patient presented with an erratic pulse and required immediate monitoring.
Examples
By Part of Speech
verb
British English
- The signal began to erratic, cutting in and out.
- (Note: 'to erratic' as a verb is exceedingly rare and non-standard)
American English
- (Not standard; the verb form is essentially unused.)
adverb
British English
- He worked erratically, sometimes for days on end, then not at all for weeks.
- The light flickered erratically before going out.
American English
- The team played erratically, winning big one night and losing badly the next.
- Shares traded erratically following the merger news.
adjective
British English
- The gardener was sacked for his erratic timekeeping.
- Britain experienced erratic rainfall throughout the summer.
American English
- Her erratic driving led to a traffic stop.
- The stock market has been highly erratic this quarter.
Examples
By CEFR Level
- The old clock ticks erratically.
- The internet connection in this area is quite erratic.
- Critics panned the actor's erratic performance in the lead role.
Learning
Memory Aids
Mnemonic
Imagine an **ERRATIC RAT** in a maze, running unpredictably in all directions, never following a consistent path.
Conceptual Metaphor
UNPREDICTABLE MOVEMENT IS ERRATIC BEHAVIOUR (e.g., 'His career path has been erratic,' mapping physical wandering onto life choices).
Watch out
Common Pitfalls
Translation Traps (for Russian speakers)
- Not 'ошибочный' (erroneous/mistaken).
- Not 'странный' (strange/weird). Closer to 'непостоянный', 'неустойчивый', 'беспорядочный'.
Common Mistakes
- Using 'erratic' to mean 'wrong' (e.g., *'Your calculation is erratic').
- Using it for a *single* unexpected event rather than a pattern (e.g., *'His arrival was erratic').
Practice
Quiz
In which context is 'erratic' LEAST appropriate?
FAQ
Frequently Asked Questions
Yes, but it's a specialised geological term for a large, irregular boulder transported by glacial ice. In general use, it's almost exclusively an adjective.
'Erratic' stresses inconsistency and unpredictability in pattern or behaviour. 'Arbitrary' stresses a lack of reason, system, or fairness, often based on random choice or personal whim.
It's common in informal speech, but purists argue 'erratic' is already an extreme adjective (like 'unique'). More formal alternatives are 'highly erratic', 'deeply erratic', or 'wildly erratic'.
From Latin 'erraticus', from 'errare' meaning 'to stray, wander'. Related to 'error' (a wandering from the truth) and 'knight errant' (a wandering knight).